1. Field of the Invention
The present invention relates to a composite substrate and a method for manufacturing the composite substrate and, in particular, to a composite substrate having a plate substrate body and a frame connected to a first major surface of the substrate body and a method for manufacturing the composite substrate.
2. Description of the Related Art
In order to highly densely mount electronic components, a module component having chip electronic components mounted on two sides or one side of a substrate body is available. In order to raise the substrate body of the module component from another circuit substrate when the module component is mounted on the circuit substrate, a frame member or a package is attached to the substrate body of the module component. In such a case, in order to electrically connect the substrate body with another circuit substrate, an interconnection line pattern is provided on the frame member or the package. One end of the interconnection pattern is connected to the substrate body, while the other end of the interconnection pattern is connected to the other circuit substrate (refer to, for example, Japanese Unexamined Patent Application Publication No. 6-216314, Japanese Unexamined Patent Application Publication No. 7-50357, Japanese Unexamined Patent Application Publication No. 2000-101348, and Japanese Unexamined Patent Application Publication No. 2001-339137).
In addition, Japanese Unexamined Patent Application Publication No. 2005-333046 describes a substrate connection member having a lead terminal that protrudes from a housing of the substrate connection member and that is used to connect module substrates. By using the spring elasticity of the protruding lead terminal, resistance to shock is improved.
Furthermore, Japanese Unexamined Patent Application Publication No. 2005-328009 describes a technology in which, as shown in FIG. 16A, a lead frame 130 is insert-molded on a plate-like resin substrate 120, a middle strip 131 of the lead frame 130 is embedded inside the resin substrate 120, and either end portion of the lead frame 130 is bent so that a chip package 110 having lead portions 132 and 133 exposed on the upper and lower surfaces of the resin substrate 120 is provided.
As shown in FIG. 16B, the chip package 110 includes a chip 140 mounted on an upper surface of the resin substrate 120 so as to bridge over an opening 123. The chip 140 is connected to the lead portion 132 using a bonding wire 150.
In addition, as shown in FIG. 16C, a resin sealer 152 is applied to the upper surface of the chip package 110 so as to seal the chip 140. Thereafter, a box-shaped cover 154 having an open bottom is disposed over the chip package 110. The box-shaped cover 154 is then secured to the resin substrate 120 so that a semiconductor device is provided. The semiconductor device is mounted on a printed substrate 171.
If the coefficients of thermal expansion or the linear coefficients of expansion of the substrate body of the module component and another circuit substrate having the module component mounted thereon are different, a thermal stress occurs in a connection portion between the interconnection line pattern provided on the frame member and the package due to a temperature change. In addition, a shock stress caused by a dropping shock may be applied. In particular, if the module component is used in a severe environment, the thermal stress and the shock stress increase, and therefore, the connection reliability significantly decreases.
Since the substrate connection member described in Japanese Unexamined Patent Application Publication No. 2005-333046 has a protruding portion of a lead terminal that is located in the air, it is difficult to accurately connect the lead terminal to a module substrate. In addition, the structure is complicated.
The chip package described in Japanese Unexamined Patent Application Publication No. 2005-328009 includes a chip mounted thereon and connected thereto using a bonding wire. The chip is not coupled to a substrate body. Japanese Unexamined Patent Application Publication No. 2005-328009 neither describes nor suggests the shape of a lead frame that reduces a thermal stress and a shock stress.